erl in ci:debug

[myobie]

These changes make the buildpack work during Heroku CI as part of a pipeline and with the ci:debug cli command.

[venkatd]

I can confirm this resolved my issue. When I use a heroku pipeline, erlang was not getting properly installed. Using this fork, I'm able to get tests passing.

[HashNuke]

@anulman since you tinkered with the buildpack recently: Does this PR still help?

[anulman]

@HashNuke I was not using Heroku's ci features. I would assume so

[myobie]

I just tested an example app using https://github.com/HashNuke/heroku-buildpack-elixir.git master and I was able to successfully run $ heroku ci:run --pipeline test-for-elixir and $ heroku ci:debug --pipeline test-for-elixir (where I ran $ mix test).

I believe this might have been fixed in master sometime after this PR was created. I feel comfortable closing this.

[DavidMikeSimon]

@myobie I'm still unable to get ci:debug working on the upstream branch, but it works great on your fork. Please consider re-opening your PR!

[myobie]

@DavidMikeSimon do you have an example repo?

[jc00ke]

I'm seeing this with an app right now. Would love to see this PR reopened and merged. ❤️

[jesseshieh]

@jc00ke do you have an example repo I can use to test? Does the fix here resolve your issue?
You can specify which branch to use when specifying which buildpack to use I believe.

[jesseshieh]

@jc00ke actually, it looks like it's just https://github.com/myobie/heroku-buildpack-elixir without a branch. Can you see if your issue is resolved with the above buildpack?

It also looks like there is a conflict that needs to be resolved. If the fix does indeed work, @myobie do you mind resolving the conflict?

[myobie]

FYI I've been using a new buildpack I created to use elixir releases and haven't been maintaining my fork. I did resolve the conflict but I didn't fully test the result.

[jc00ke]

@jesseshieh will give it a try on Monday!

[jc00ke]

@jesseshieh worked great!

[jesseshieh]

Just tested on a basic, non-heroku-ci deploy and all seemed to work fine. I'm slightly worried about merging this because I'm not sure I understand all the different edge cases if any, but these changes seem to solve a demonstrated problem and I haven't found any regressions. I also can't think of any reason why this would break any existing apps, but that is based on my less than perfect knowledge of how this buildpack works as a new maintainer. There aren't great tests to verify that this doesn't break anything, but I'm okay with merging this in the interest of moving forward rather than freezing the buildpack from any new features or complicated bug fixes.

[jesseshieh]

Sorry guys, looks like this caused deploy failures for a number of people in #167. I haven't figured out exactly what is happening, but I had to revert this PR.